Common Diagnostic Approaches

Common Diagnostic Approaches

There are a number of commonly used approaches to diagnose an FASD. The four most common approaches are listed below along with a brief description of each, followed by a short commentary on the utility of each approach. Research indicates that all of the approaches outlined have their strengths and weaknesses, therefore no one approach is recommended over the other. It is best to work within a multidisciplinary team to conduct the most comprehensive assessment of each child.

The primary goal of these guidelines is to provide standard diagnostic criteria for FAS so that consistency in the diagnosis can be established for clinicians, scientists, and service providers.

The National Task force on FAS and FAE “Guidelines for Referral and Diagnosis” are thoroughly considered and consensus-derived and have high clinical specificity, but address only FAS; they do not offer diagnostic criteria for other FASDs.

The 4-digit code uses quantitative, objective measurement scales and specific case definitions. The 4 digits in the code reflect the magnitude of expression of the 4 key diagnostic features of FAS in the following order: (1) growth deficiency, (2) the FAS facial features, (3) central nervous system (CNS) damage/dysfunction, and (4) prenatal alcohol exposure. The magnitude of expression of each feature is ranked independently on a 4-point Likert scale with 1 reflecting complete absence of the FAS feature and 4 reflecting a strong "classic" presence of the FAS feature.

The University of Washington approach is more objective, has higher clinical specificity, and places more emphasis on accuracy of the exposure history; as a result it is in effect more exclusive.

In the proposed clarifications of the Institute of Medicine (IOM) criteria, children with FAS (with or without confirmed maternal alcohol exposure) must have abnormalities in all domains, facial dysmorphic features, growth, and brain growth or structure. In the partial FAS category (with or without confirmed maternal alcohol exposure), children must display typical facial dysmorphic features and abnormalities in one of the other domains (growth or CNS structure or function).

The revised IOM approach is arguably more intuitive and subjective, and relies on (or allows more room for) clinical judgment. It is likely less specific but more inclusive. In general, the terminology it uses is more within the reach of families, other caregivers, and adult patients.